The present invention generally relates to a rock drill and more particularly, to a boom positioning apparatus for positioning a boom of the rock drill, which enables accurate drilling of the rock drill through elimination of errors due to vibrations and deflection of the boom.
Previously, the assignee assigned by the present inventor proposed in U.S. Pat. No. 4,240,511, a boom positioning apparatus in which an automatic positioning program of the boom can be composed easily by expressing a desired position of the drilling apparatus mounted on the boom in a rectangular coordinate system and a foremost position of the boom is designated numerically such that the boom can be rapidly positioned at a desired position. This known boom positioning apparatus has such an advantage that the boom can be rapidly positioned at the desired position. However, the known boom positioning apparatus is disadvantageous in that since a drilling operation is performed through automatic positioning of the boom by numerically inputting data of a drilling pattern, the boom may not be positioned at a predetermined position due to vibrations of a hinge for the boom, a machining error of length of the boom, deflection of the boom, control errors, etc.